Assessment Of Development Methods For Tuo Block 25 A Heavy Oil Reservoir

As the exploration and production of oil and gas resources progresses,the type and nature of reserves that are available for production keeps changing.Conventional reservoirs with vast areal spread and thick oil-bearing layers are becoming harder and harder to find thus giving way to unconventional and more technologically challenging reservoirs.These unconventional resources also account for almost 70% of the total hydrocarbon reserves in the world.They include heavy oil,tight oil,shale gas etc.This therefore makes finding and researching efficient and cost-effective methods of extracting these resources of utmost importance.Tuo block 25 which is located in Liaohe Oilfield is a heavy oil reservoir characterized by low permeability and low porosity yet with oil having considerably high viscosity.This work takes Tuo block 25 as a case study to investigate production of heavy oil from reservoirs with such characteristics.It focuses on using scientific screening and evaluation methods to determine the suitable production regime for this block.The MATLAB software is employed to do the preliminary screening after which comparison with nearby blocks of similar characteristics is made from which cold-water flooding,hot water flooding,cyclic steam stimulation and steam injection are simulated and evaluated for their economic suitability to this block.From the results obtained in this study,we observe that due to the large reservoir depth,heat loss in the well bore and formation,factors like high wax content,low porosity and low permeability of the reservoir,compared with other methods such as steam flooding,hot water flooding is the most economically sound production method that should be employed,after economic analysis,its NPV is much higher than all other methods.Through hot water flooding,the recovery factor of this block can be additionally increased by nearly 10%,to give a total recovery rate of 43%.Therefore,it is recommended to use hot water flooding as the best means for improving the recovery rate of Tuo block 25.